Suxamethonium associated hypertonicity and cardiac arrest in unsuspected pseudohypertrophic muscular dystrophy.

In 1971 a patient with suxamethonium-induced cardiac arrest in an unsuspected case of pseudohypertrophic muscular dystrophy was described (Genever, 1971). Suxamethonium has been implicated in several cases of muscular rigidity, hyperkalaemia and cardiac arrest and in malignant hyperpyrexia, and there is evidence that these reactions occur often when there are pre-existing muscular disorders including muscular dystrophies, hernias (Ellis and Halsall, 1980) and strabismus (Tammistoa et al., 1970). The mechanisms are unknown. A second patient with cardiac arrest in unsuspected pseudohypertrophic (Duchenne) muscular dystrophy is reported in this paper. In this case, however, there was a significant difference in that cardiac arrest was preceded by rigidity, cyanosis and acidosis.